This invention relates to a process for gasifying hydrocarbons, and more particularly to a process for gasifying hydrocarbons using a catalyst composed of K.sub.2 O--CaO--Al.sub.2 O.sub.3 system which retains high catalytic activity for a long period of time.
Many kinds of catalysts for gasifying hydrocarbons are known, for example, the K.sub.2 O--Al.sub.2 O.sub.3 system catalyst (Japanese Patent Publication No. 8521/1972), and the K.sub.2 O--CaO--Al.sub.2 O.sub.3 system catalyst (Japanese Patent Laid-Open Publication (Kokai) No. 126590/1974). The K.sub.2 O--Al.sub.2 O.sub.3 system catalyst is advantageous in that it produces a gas having a large amount of hydrogen. It also prevents the formation of tar because it has high activity for gasifying and can readily split the C--H bond. Said K.sub.2 O--Al.sub.2 O.sub.3 catalyst has a number of disadvantages, i.e., the potassium is readily volatilized at high temperature, and its activity is not retained for long periods of service. The K.sub.2 O--CaO--Al.sub.2 O.sub.3 system catalyst produces a gas having a high calorific value and also prevents the formation of coke because it can easily split the C--C bond. However, because it cannot prevent the formation of tar which causes piping to be clogged, it is difficult to use this type of catalyst in practice.
We carried out extensive studies to develop an excellent catalyst in which the above-mentioned advantages of the K.sub.2 O--Al.sub.2 O.sub.3 system catalyst and the K.sub.2 O--CaO--Al.sub.2 O.sub.3 system catalyst are retained but the disadvantages thereof are eliminated.